국내 맥상광체조사를 위한 3차원 전기비저항 모델링자료의 3차원 역산 해석

Abstract

Department of Energy Systems Engineering, Seoul National University, Seoul 151-744, KoreaAbstact:r Recently as the interest in the development of domestic ore deposits has increased, we can easily find somestudies on exploration geophysics-based ore-deposit survey in literature. Based on the fact that mineralized zone aregenerally more conductive than surrounding media, electrical resistivity survey among several geophysical surveys hasbeen applied to investigate metallic ore deposits. Most of them are grounded on 2-D survey. However, 2-D inversion maylead to some misinterpretation for 3-D geological structures. In this study, we investigate the feasibility of the 3-Delectrical resistivity survey to 3-D vein-type ore deposits. We first simulate 2-D dipole-dipole survey data for survey linesnormal to the strike and 3-D pole-pole survey data, and then perform 3-D inversion. For 3-D ore-body structures, weassume a width-varying dyke, a wedge-shaped, and a fault model. The 3-D inversion results are compared to 2-Dinversion results. By comparing 3-D inversion results for 2-D dipole-dipole survey data to 3-D inversion results for 3-Dpole-pole survey data, we could note that the 2-D dipole-dipole survey data yield better inversion results than the 3-Dpole-pole data, which is due to the main characteristic of the pole-pole array. From these results, we are convinced that ifwe have certain information on the direction of the strike, it would be desirable to apply 2-D dipole-diple survey for thesurvey lines normal to the strike. However, in most cases, we do not have any information on the direction of the strike,because we already developed the ore deposit with the outcrops and the remaining ore deposits are buried under thesurface. In that case, performing 3-D pole-pole electrical resistivity survey would be a reasonable choice to obtain moreaccurate interpretation on ore body structure in spite of low resolution of pole-pole array. 3-D, dipole-dipole array, pole-pole array, electrical resistivity survey, inversion :           ! # $ ' %& * () +,- & / . 0 12 .  34  56 , / 7 89 :; > @ AB * C, E D, FG > : * ,- HI J M KL& , NO  EP R Q 2 ST /  U2 HI .X VW  34 R Q  Y'  RZ, M 1' , Y [ 2\X 9  Y ]^ ; ` _ 1-$ a6 bc 3 ST d* e2 .  fg 3 ST hd ,E 2 ST   2 ST j ;i k HI 56 U lm